I've just discovered what seems to be a similar error to this GZDoom issue. My native desktop resolution is 1600x900, and when I'm running ECWolf 1.3.3 (w/ Wolf3D shareware v1.4 data files) in fullscreen mode with the 4:3 aspect ratio set in the menu, the game screen is actually rendered in 5:4 ratio, making the images overstretched vertically (pillarboxed areas have been removed from the screenshots):

ECWolf_menu.png (24.72 KiB) Viewed 632 times

ECWolf_Gameplay.png (58.94 KiB) Viewed 632 times

For comparison, here's an original DOS version screenshot corrected to 640x480: